1. Field of the Invention
This invention relates to sample applicators for analytical assays.
2. Description of the Related Art
Various types of sample applicators for analytical assays have been disclosed. Sample applicators specifically for blood sample assays are also known in the art. See, for example, U.S. Pat. Nos. 6,036,659; 6,177,283; 6,258,045; 6,265,223; and 6,309,887. Applying a uniform volume and/or shape of a sample to an assay device can be important to optimize performance of the assay. Previous systems attempt, through various methods, to apply a predetermined volume of liquid in a uniform distribution to an assay. For example, U.S. Pat. No. 4,334,879 discloses an applicator blade capable of absorbing sample and being pressed onto an applicator film. U.S. Pat. No. 5,405,516 discloses an applicator with a planar projecting element and a stiffening element that employs a hydrophobic mixture on the applicator to avoid sample leaching or blotting of an assay. U.S. Pat. No. 6,544,395 discloses an applicator blade with an applicator tip and a barrier that limits an amount of liquid the sample applicator may retain. Such systems and methods may also require separation of liquid sample (by the sample applicator) or other treatment of the sample or of the sample applicator prior to the administration of the sample to the assay.